In conventional semiconductor devices such as field effect transistors (FETs) and high electron mobility transistors (HEMTs), a through hole is provided in a semiconductor substrate immediately below a source electrode. A grounding conductor is provided on the back surface of the semiconductor substrate, including the inner surface of the through hole so that the grounding conductor is in contact with the source electrode.
Such conventional semiconductor devices are mounted on amounting substrate by interposing Au—Sn solder between the grounding conductor and grounding wiring of the mounting substrate.